There is a strong likelihood that Luke Sharp is a pseudonym of Alkis Alkiviades. The reasons are manifold and made clear in the article on Luke Sharp. If this is the case, then the character Alkis Fearslicer, who appears in both Chasms of Malice and Daggers of Darkness is potentially a cameo appearance. Interestingly, in the one picture of Alkis Fearslicer in Daggers of Darkness, his back is facing towards you so you cannot see his face to confirm the cameo.[2]